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Title: Geophysical exploration and hydrologic impact of the closed Gracelawn landfill in Auburn, ME

Conference · · Geological Society of America, Abstracts with Programs; (United States)
OSTI ID:5582081
 [1]
  1. Bates Coll., Lewiston, ME (United States). Geology Dept.

Several geophysical methods were used over portions of the Gracelawn landfill, in Auburn, Maine to determine the surface boundaries and subsurface structure of this closed landfill, and to determine the landfill's effects on groundwater quality. The landfill was originally a sand and gravel pit excavated in the 1950's and early 1960's, and was used as a landfill from 1964--1977. The site is unlined, has a clay cap, and has been graded and developed as a baseball park. Two seismic refraction lines were performed to obtain a minimum depth to bedrock of 80 m. Seismic velocities of methane gas-saturated trash ranged from 250 to 340 m/s, and sand velocities are approximately 800 m/s. Two electrical resistivity Wenner surveys over the trash yielded the depth to saturated material and thickness of the trash layers. Resistivity values for dry refuse ranged from 1,000-2,000 [Omega]*m. A third electrical resistivity survey yielded the thickness of unsaturated and saturated sands bordering the landfill. Dry sands were found to have a resistivity of 1,000 [Omega]*m, and saturated sands a resistivity of 500 [Omega]*m. Gravity and magnetic survey grids across the site revealed anomalies which were mapped to illustrate the irregular morphology of the buried trash as well as its surface boundaries. Residual magnetic anomalies are on the order of 2,000 nT. Residual gravity anomalies are up to 5 mGal. Groundwater elevations determined by the geophysical survey, combined with a survey of existing water monitoring well logs, indicate that the groundwater flow in the sand and gravel aquifer is to the southeast, away from the public water supply, Lake Auburn, which lies to the north of the site. However, correlations between the bedrock fracture analysis and the geophysical survey illustrate that there is potential for contamination of Lake Auburn via the bedrock aquifer.

OSTI ID:
5582081
Report Number(s):
CONF-9303211-; CODEN: GAAPBC
Journal Information:
Geological Society of America, Abstracts with Programs; (United States), Vol. 25:2; Conference: 28. annual Geological Society of America (GSA) Northeastern Section meeting, Burlington, VT (United States), 22-24 Mar 1993; ISSN 0016-7592
Country of Publication:
United States
Language:
English